Noise abatement in a venturi valve

ABSTRACT

A venturi valve having a valve housing that includes a narrowing section extending between a broader upstream end and a narrower valve throat followed by a broadening section downstream of the valve throat, and a valve member configured to be situated in the valve housing and movable along a valve axis in an axial direction of the valve housing. The venturi valve includes a plurality of flow influencing features positioned in a reattachment region of the valve member and/or extending inward from an inner wall of the valve housing. The plurality of flow influencing features are configured to reduce perturbations in an air flow passing through the venturi valve thereby reducing rattle from the venturi valve.

TECHNICAL FIELD

The present disclosure relates generally to HVAC (Heating, Ventilationand/or Air Conditioning) systems, and more particularly, to systems andmethods for reducing rattling noises radiating from venturi valves usedin HVAC systems.

BACKGROUND

HVAC (Heating, Ventilation and/or Air Conditioning) systems ofteninclude venturi valves for regulating the amount of airflow throughairducts that lead to various rooms, zones or other areas of a building.Venturi valves typically include a valve member movable within a valvehousing. The valve housing defines a venturi restriction, which is oftenhourglass shaped. The position of the valve member within the valvehousing determines the valve's restriction to airflow, and thusdetermines the amount of airflow that passes through the venturi valve.

In some cases, the valve member includes a bias mechanism, such as aspring, that is compressed by an amount that is dependent on theincoming air pressure of the incoming airflow, which slides the valvemember along a valve member support toward the venturi restriction inthe valve housing. This restricts the airflow that flows through theventuri valve with increasing incoming air pressure. When so provided,the airflow through the venturi valve may be largely independent of theincoming air pressure, which allows the venturi valve to deliver arelatively constant airflow into a room, zone or other area even whenthe pressure of the incoming airflow significantly varies.

In some cases, such venturi valves, particularly larger sized valves,can produce a rattling noise over a significant portion of the valverange of airflows and pressures. This is believed to be caused byvortices that form in the airflow around the valve member. Thealternating shedding of these vortices is believed to induce lateralvibration in the valve member, causing the valve member to vibrateagainst the valve member support causing a rattling noise. As such,during normal operation, a conventional venturi valve will often radiatea rattling noise at higher flowrates, which can be amplified within theductwork of the HVAC system. What would be desirable is a method andsystem that allows the venturi valve to operate at higher flowrateswhile eliminating or substantially decreasing any audible noiseemanating from the venturi valve.

SUMMARY

The present disclosure relates generally to HVAC systems and moreparticularly to systems and methods for reducing rattling noisesradiating from venturi valves used in HVAC systems. In one example, aventuri valve includes a valve housing that has a narrowing sectionextending between a broader upstream end and a narrower valve throat. Avalve member is situated in the valve housing and movable along a valveaxis in an axial direction of the valve housing. The valve member mayhave a length extending in the axial direction of the valve housing, anda width extending in a direction transverse to the axial direction ofthe valve housing. The valve member may include a maximum width regionthat defines a maximum width of the valve member. The valve member maydefine a reattachment region downstream of the maximum width region,wherein the reattachment region may be configured to cause air flowingover the maximum width section to reattach to the valve member in thereattachment region.

In another example, a valve housing for a venturi valve may include anarrowing section extending between a broader upstream end and anarrower valve throat followed by a broadening section downstream of thevalve throat. The narrowing section, the valve throat and the broadeningsection are defined by an inner wall of the valve housing. The valvehousing may include a plurality of flow influencing features that extendinward from the inner wall of the valve housing at the valve throatand/or in the broadening section of the valve housing. The plurality offlow influencing features may be configured to reduce perturbations inan air flow passing along the inner wall of the valve housing.

In another example, a venturi valve may include a valve housing that hasa narrowing section extending between a broader upstream end and anarrower valve throat followed by a broadening section downstream of thevalve throat. The narrowing section, the valve throat and the broadeningsection may be defined by an inner wall of the valve housing. Theventuri valve may include a valve member that is configured to besituated in the valve housing and is movable along a valve axis in anaxial direction of the valve housing. The valve member may have a lengthextending in the axial direction of the valve housing and a widthextending in a direction transverse to the axial direction of the valvehousing. The venturi valve may include one or more of: (1) the valvemember has a maximum width region that defines a maximum width of thevalve member, and a reattachment region downstream of the maximum widthregion, wherein the reattachment region is configured to cause airflowing over the maximum width section to reattach to the valve memberin the reattachment region; and (2) the valve housing includes aplurality of flow influencing features extending inward from the innerwall of the valve housing at the valve throat and/or in the broadeningsection of the valve housing, wherein the plurality of flow influencingfeatures are configured to reduce perturbations in an airflow passingalong the inner wall of the valve housing.

The preceding summary is provided to facilitate an understanding of someof the innovative features unique to the present disclosure and is notintended to be a full description. A full appreciation of the disclosurecan be gained by taking the entire specification, claims, figures, andabstract as a whole.

BRIEF DESCRIPTION OF THE FIGURES

The disclosure may be more completely understood in consideration of thefollowing description of various examples in connection with theaccompanying drawings, in which:

FIG. 1 is a schematic side view of an example venturi valve for use inan HVAC system, wherein a valve member of the venturi valve is shown ina position of minimum air flow;

FIG. 2 is a schematic side view similar to FIG. 1, showing the valvemember at a minimum open position;

FIG. 3 is a schematic side view similar to FIG. 1, showing the valvemember at a maximum open position;

FIG. 4 is a perspective view of an example valve member which may beused in the venturi valve of FIG. 1, the valve member including flowinfluencing features on a reattachment region of the valve memberincluding a plurality of protrusions;

FIG. 5 is a schematic side view of the example valve member of FIG. 4;

FIG. 6 is a perspective view of an example valve member which may beused in the venturi valve of FIG. 1, the valve member including flowinfluencing features on a reattachment region of the valve memberincluding a plurality of dimples;

FIG. 7 is a schematic side view of the example valve member of FIG. 6;

FIG. 8 is a schematic side view of an example valve member which may beused in the venturi valve of FIG. 1, the valve member including anelongated reattachment region;

FIG. 9 is a schematic side view of an example valve member which may beused in the venturi valve of FIG. 1, the valve member including anabbreviated reattachment region;

FIG. 10 is a perspective view of an example valve member which may beused in the venturi valve of FIG. 1, the valve member including a groovein a reattachment region of the valve member;

FIG. 11 is a schematic side view of the example valve member of FIG. 10;

FIG. 12 is a schematic side view of an example valve member which may beused in the venturi valve of FIG. 1, the valve member including flowinfluencing features in a reattachment region of the valve memberincluding a plurality of riblets;

FIG. 13 is a schematic side view of an example venturi valve, wherein avalve throat of the venturi valve includes a plurality flow influencingfeatures;

FIG. 14 is a schematic end view showing the valve throat of the venturivalve of FIG. 13, the valve throat including flow influencing features;

FIG. 15 is a schematic end view showing the valve throat of the venturivalve of FIG. 13, the valve throat including flow influencing features;

FIG. 16 is a schematic side view of an example venturi valve, wherein avalve throat of the venturi valve includes flow influencing features anda valve member includes flow influencing features on a reattachmentregion of the valve member;

FIG. 17 is a schematic end view showing the valve throat of the venturivalve of FIG. 16, the valve throat including flow influencing featuresand the valve member includes flow influencing features on areattachment region of the valve member;

FIG. 18 is a graph illustrating points of audible rattling and norattling at various flow rates and differential pressure of a valvemember as in FIGS. 1-3;

FIG. 19 is a graph illustrating points of audible rattling and norattling at various flow rates and differential pressure of the valvemember as in FIGS. 4-5;

FIG. 20 is a graph illustrating points of audible rattling and norattling at various flow rates and differential pressure of the valvemember as in FIGS. 6-7;

FIG. 21 is a graph illustrating points of audible rattling and norattling at various flow rates and differential pressure of the valvemember as in FIG. 8;

FIG. 22 is a graph illustrating points of audible rattling and norattling at various flow rates and differential pressure of the valvemember as in FIG. 9;

FIG. 23 is a graph illustrating points of audible rattling and norattling at various flow rates and differential pressure of the valvemember as in FIGS. 10-11;

FIG. 24 is a graph illustrating points of audible rattling and norattling at various flow rates and differential pressure of the valvemember as in FIG. 12;

FIG. 25 is a graph illustrating points of audible rattling and norattling at various flow rates and differential pressure of the valvethroat as in FIG. 14;

FIG. 26 is a graph illustrating points of audible rattling and norattling at various flow rates and differential pressure of the valvethroat as in FIG. 15;

FIG. 27 is a graph illustrating points of audible rattling and norattling at various flow rates and differential pressure of the valvethroat and the valve member as in FIGS. 16-17;

FIG. 28A is a wave graph illustrating a level of sound created over timeby the valve member as in FIGS. 1-3; and

FIG. 28B is a wave graph illustrating a level of sound created over timeby the valve member as in FIGS. 4-5.

While the disclosure is amenable to various modifications andalternative forms, specifics thereof have been shown by way of examplein the drawings and will be described in detail. It should beunderstood, however, that the intention is not to limit the disclosureto the particular examples described. On the contrary, the intention isto cover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the disclosure.

DESCRIPTION

The following description should be read with reference to the drawings,in which like elements in different drawings are numbered in likefashion. The drawings, which are not necessarily to scale, depictexamples that are not intended to limit the scope of the disclosure.Although examples are illustrated for the various elements, thoseskilled in the art will recognize that many of the examples providedhave suitable alternatives that may be utilized.

The present disclosure relates generally to HVAC (Heating, Ventilation,and/or Air Conditioning) systems and more particularly, to systems andmethods for reducing rattling noises radiating from venturi valves usedin HVAC systems. Some examples of venturi-style valves include theAccel-2 Venturi valve by Phoenix Controls, the Supreme Air Venturi by EHPrice, the Triatek valve, and the Venturi FX valve by Antec Controls.

In some examples, an HVAC system may include a blower, at least onesupply airduct, a return airduct, at least one VAV (variable air volumevalve), such as a venturi valve as discussed herein, and a controller(e.g., a computing system). Air discharged from an outlet of the blowerflows through the supply airduct through one or more valves, into acomfort zone (e.g., a room, area or space within a building), throughthe return airduct, and then back to a suction inlet of the blower toperpetuate the cycle. The controller may control the opening of eachvalve to adjust the amount of airflow delivered to the comfort zone. Thecontroller may also control the blower and/or one or more other HVACcomponents of the HVAC system.

FIG. 1 is a schematic side view of an example venturi valve 10 that maybe used in an HVAC (Heating, Ventilation, and/or Air Conditioning)system, wherein a valve member 40 of the venturi valve 10 is shown in aposition of minimum air flow. The HVAC system (not shown) may includeany apparatus or collection of devices use for heating, ventilating,cooling, filtering, humidifying, dehumidifying, blowing, compressing,regulating, and/or conveying air. The venturi valve 10, which may be anexample of a VAV valve (variable air volume valve), may include anydevice for adjusting or modulating air flow. In some examples, as shownin FIG. 1, the venturi valve 10 may be used in the HVAC system fordelivering air to a comfort zone (e.g., a room, zone, area or spacewithin a building).

In some examples, and with reference to FIG. 1, the venturi valve 10 mayinclude a valve housing 12 with a curved nozzle section 36 extendingbetween a broader upstream end 13 and a narrower downstream end 11, avalve member 40 movable in an axial direction 17 through the nozzlesection 36, a valve member support shaft 19 (e.g., rod, bar, tube, etc.)extending through the valve member 40, at least one bracket 21 attachedto the housing 12 for supporting the shaft 19 and the valve member 40, avalve throat 20 at the narrower downstream end 11 of nozzle section 36,and an actuator system 22 for moving the position of valve member 40within nozzle section 36 to adjust the airflow 100 through the valve 10.Some examples of the housing 12 are made of sheet metal formed in agenerally hourglass shape (e.g., round or rectangular cross-section).

In the illustrated example of FIG. 1, the bracket 21 includes aplurality of spoke-like arms 24 extending in a radial direction 23between the shaft 19 and an inner wall 16 of the housing 12. A hub-likecentral sleeve 35 of the bracket 21 provides the shaft 19 with radialsupport yet has sufficient clearance to allow the actuator system 22 toslide the shaft 19 in the axial direction 17 relative to the sleeve 35and the housing 12. The shaft 19 is coupled to the valve member 40, sothe actuator system 22 can move the valve member 40 by moving the shaft19.

In some examples, the actuator system 22 comprises an actuator 25 and alinkage 26. The linkage 26 mechanically couples the actuator 25 to shaft19. The term, “actuator” refers to any apparatus capable of moving thevalve member 40. Some examples of the actuator 25 include an electricmotor, a servomotor, a stepper motor, a universal motor, a brushless DCmotor, a linear motor, a pneumatic cylinder, a bellows, a drive screw, aroller chain, a cogged belt, a spring, and various combinations thereof,etc. The term, “linkage” refers to any structure capable of directly orindirectly transmitting a force 27 from the actuator 25 to move thevalve member 40. Some examples of a linkage 26 include a lever arm 28;one or more pivotal connections 29, 30, 31, and 32; a link 37 betweenthe lever arm 28 and the shaft 19; a chain, a cable, a rod, a spring,and various combinations thereof.

In some examples, a position sensor 33 is operatively coupled to thelever arm 28 of the actuator system 22. The position sensor 33 providesa controller (not shown) with a feedback signal that indicates theposition of the valve member 40. With reference to the feedback signal,the controller provides an output signal that commands the actuator 25to move the valve member 40 to various desired positions such as acommanded position.

The term, “position sensor” refers to any device for monitoring amovable member's location, wherein the device provides a feedback signalthat varies in response to changes in the member's location, and therebyprovides at least some indication of the member's position. Someexamples of such movable members include linkage 26, actuator 25, shaft19, valve member 40, etc. Some examples of position sensor 33 include apotentiometer coupled to the lever arm 28 for sensing its angularposition, an encoder, a resolver, a pulse counter, a Hall effect sensor,one or more electromechanical limit switches, a proximity sensor, etc.

In some examples, the valve member 40 is rigidly attached to the shaft19, so the two may move as a unit. In the illustrated example, however,the valve member 40 is coupled to the shaft 19 in a resilient way thatallows some limited axial movement between the valve member 40 and theshaft 19. Such movement allows the valve member 40 to automaticallyshift its placement on the shaft 19 in response to changes in static airpressure across the valve member 40. This enables the venturi valve 10to automatically compensate for changes in static air pressure withoutthe actuator 25 having to make such corrections. So, under some varyingpressure conditions (e.g., 0.3 to 3 inches static water column), theactuator 25 and the shaft 19 can remain substantially stationary while achange in static pressure automatically adjusts the position of thevalve member 40 to maintain a substantially constant volume of airflowthrough the valve 10.

In the illustrated example, the venturi valve 10 includes a spring 54, aspring collar 55, and a cylinder 59 disposed within the valve member 40;two end caps 57 attached to the valve member 40; an upstream collar 52on the shaft 19; and a downstream collar 53 on the shaft 19. In someexamples, the valve member 40 includes a valve seal 58 that can sealupon valve throat 20 at the narrower downstream end 11 of the nozzlesection 36.

Collars 52 and 53 are spaced apart and affixed to the shaft 19. End caps57 on the valve member 40 are in slip-fit relationship with the shaft19. This provides the valve member 40 with the freedom to slide axiallyalong the shaft 19 within the stopping limits of collars 52 and 53.

The spring 54 and the spring collar 55 provide an axially resilientconnection between the valve member 40 and the shaft 19. In theillustrated example, the spring 54 is a compression spring with one endconnected to one of the end caps 57. The spring's other end connects tospring collar 55. The cylinder 59 provides the spring 54 with radialsupport. The spring collar 55 is affixed to the shaft 19. Axial movementof the shaft 19 is transmitted to the spring collar 55, the spring 54,and one end cap 57; and the valve member 40 moves in response tomovement of the shaft 19.

In addition, the resilience of the spring 54 provides the valve member40 with some freedom to move while the shaft 19 is stationary. Suchrelative movement enables the valve member 40 to slide along the shaft19 toward a more closed position in response to an increase in a deltastatic pressure across the valve member 40. Conversely, the valve member40 can move toward a more open position in response to a decrease indelta static pressure.

FIG. 1 shows an approved operational airflow range 110 extending betweena minimum airflow 112 and a maximum airflow 111. The term, “approvedoperational airflow range” refers to a predetermined normal range ofoperation. As for the minimum airflow 112 and maximum airflow 111, theterms, “minimum” and “maximum” refer to predetermined values and notnecessarily absolute values. For example, the position of a valve can beadjusted over a predetermined approved range (normal operating range)between predetermined minimum and maximum positions, yet in some casesit is still possible to move the valve beyond the approved range, i.e.,greater than the predetermined maximum or less than the predeterminedminimum, but this is not required.

FIG. 2 is a schematic side view similar to FIG. 1, but shows the valvemember 40 at a minimum open position 38. In the illustrated example, theminimum open position 38 is closer to being fully closed than when theventuri valve 10 is configured for minimum airflow 112 (FIG. 1). So, inthe example shown in FIG. 2, the minimum open position 38 is less thanthe approved operational airflow range 110. In other examples, however,the minimum open position 38 is right at the minimum airflow 112(FIG. 1) and thus is within the approved operational airflow range 110.

FIG. 3 is a schematic side view similar to FIG. 1, but shows the valvemember 40 at a maximum open position 39. In the illustrated example,maximum open position 39 is more open than when the venturi valve 10 isconfigured for maximum airflow 111 (FIG. 1). So, in the example shown inFIG. 3, the maximum open position 39 is beyond the approved operationalairflow range 110. In other examples, however, the maximum open position39 is right at the maximum airflow 111, and thus is within the approvedoperational airflow range 110.

During use, airflow engages an upstream cone 63 of the valve member 40and is diverted towards a maximum width region of the valve member. Thisairflow is accelerated toward the maximum width region, and thenabruptly decelerates as it passes the maximum width region. While thevelocity decreases, the air pressure increases in a region outside of aboundary layer that extends along the surface of the valve member 40.Since the variation of pressure across the boundary layer issignificant, air particles within the boundary layer experiencerelatively larger deceleration to the point of changing the direction ofthe air flow near the surface of the valve member 40. The air flowseparation from the surface of the valve member 40 introduces vorticesin the wake that forms downstream of the maximum width region of thevalve member 40. The alternating shedding of these vortices is believedto induce lateral vibration in the valve member 40, causing the valvemember to vibrate against the valve member support shaft 19 resulting ina rattling noise. As such, during normal operation, a conventionalventuri valve 40 will often radiate a rattling noise at higherflowrates, which can be amplified within the ductwork of the HVACsystem.

FIGS. 4-17 illustrate example embodiments of valve members (FIGS. 4-12and 16-17) that define various reattachment regions sometimes with flowinfluencing features, and valve throats (FIGS. 13-17) that may includevarious flow influencing features. The various reattachment regionsand/or the plurality of flow influencing features may be configured tomodify the airflow through the valve to reduce vortices and thus rattleemanating from the valve.

In FIGS. 4-12 and 16-17, the valve element includes a reattachmentregion just downstream of the maximum width region of the valve member.The reattachment region is configured so that the flow of air over themaximum width region reattaches to the surface of the valve member,which may significantly reduce the turbulence kinetic energy in the flowfield, and therefore eddies formed in the turbulent air flow. This alonemay significantly reduce vortex formation and vortex shedding downstreamof the maximum width region of the valve member. In some cases, and withthe airflow reattached, it is contemplated that the reattachment regionmay include one or more flow influencing features that modify thereattached airflow, such as straighten or partially laminarize thereattached airflow along the reattachment region. This may furtherreduce vortex formation and vortex shedding downstream of the maximumwidth region of the valve member, thereby further reducing rattleemanating from the valve. In some cases, the reattached air flow may beallowed to separate from the valve member within a separation regionthat is downstream of the reattachment region. The separation of the airflow from the valve member in the separation region has a considerablyless effect on rattle. In FIGS. 13-17, flow influencing features may beincluded within the valve throat and/or upstream and/or downstream ofthe valve throat to reduce vortex formation and vortex sheddingdownstream of the valve throat.

FIGS. 4 and 5 illustrate an example embodiment of a valve member 80,which may be used in the example venturi valve 10 of FIG. 1. FIG. 4 is aperspective view of the valve member 80, and FIG. 5 is a schematic sideview of the valve member 80. The valve member 80 may include a cone 81and a funnel 82. The cone 81 is positioned upstream of the funnel 82.The cone 81 may be curved and may include a hemispherical, or domeshape, while the funnel 82 may include a frustoconical shape. The cone81 and the funnel 82 may be configured such that when the valve member80 is assembled, a larger end of the funnel 82 may fit within an openend of the cone 81, although this is not explicitly shown.

As shown in FIG. 4, the valve member 80 may include a plurality ofdistinct flow influencing features 70, which may include a plurality ofprotrusions 83. In the example shown, the plurality of protrusions 83include two rows of hemispherical protrusions 83, which are spaced fromone another and staggered on a reattachment region (shown in FIG. 5) ofthe valve member 80. While the valve member 80 is shown as including tworows of the plurality of protrusions 83, it is contemplated that thevalve member 80 may include one row of the plurality of protrusions 83,three rows of the plurality of protrusions 83, four rows of theplurality of protrusions 83, or any other suitable number of rows, asdesired. In some cases, each row of the plurality of protrusions 83 mayinclude eighty protrusions 83. In some cases, each row of the pluralityof protrusions 83 may include twenty protrusions, forty protrusions,fifty protrusions, one hundred protrusions, or any other suitable numberof protrusions. While the plurality of protrusions 83 are shown ashaving a hemispherical shape, it is contemplated that the plurality ofprotrusions 83 may include a conical shape, a cube shape, a cylindricalshape, a rectangular shape, or any other suitable shape. In some cases,the plurality of protrusions 83 may each include a diameter of 0.25inches. In some cases, the plurality of protrusions 83 may include adiameter of 0.12 inches, 0.3 inches, 0.5 inches, or any other suitablediameter.

As shown in FIG. 5, the valve member 80 includes a central axis 87,which may extend centrally along a length of the valve member 80, amaximum width region 79, which may define the maximum width 84 of thevalve member 80, a reattachment region 85, which may be positioneddownstream of the maximum width region 79, and a separation region 86,which may be positioned downstream of the reattachment region 85. Themaximum width region 79 may be positioned at a point on the cone 81where the cone 81 and the funnel 82 meet. The curved, hemisphericalshape of the cone 81 may be positioned upstream of the maximum widthregion 79, and thus may be configured to divert air flow towards themaximum width region 79.

The reattachment region 85 may include an upstream end 50 and adownstream end 51. A first axis 88 may extend out from the upstream end50 of the reattachment region 85. A second axis 89 may extend from theupstream end 50 of the reattachment region 85 to the downstream end 51of the reattachment region 85. The first axis 88 is parallel with thecentral axis 87 of the valve member 80, and the second axis 89intersects the central axis 87 of the valve member 80 as shown. Thefirst axis 88 and the second axis 89 define an angle 77. The angle 77may be within a range of five (5) to forty (40) degrees. In some cases,the angle 77 may be between 25 and 35 degrees. These are just examples.The length of the reattachment region 85 may be 0.25 inches to 3 inches,0.5 inches to 2 inches, 0.5 inches to 1.5 inches, or any other suitablelength. The reattachment region 85 may be a straight surface extendingfrom the upstream end 50 to the downstream end 51, or may be curvedsurface.

In some cases, as shown in FIG. 5, the reattachment region 85 mayinclude the plurality of flow influencing features 70, which may includethe plurality of protrusions 83, as discussed with reference to FIG. 4.The reattachment region 85 may be configured to cause air flowing overthe maximum width region 79 to reattach to the valve member 80 in thereattachment region 85. Having the airflow reattach in the reattachmentregion 85 allows the plurality of protrusions 83 to influence thereattached airflow, such as straighten or partially laminarize thereattached airflow along the reattachment region 85. While not required,the air flow that reattaches to the valve member 80 in the reattachmentregion 85 may be separate from the valve member 80 within a separationregion 86.

FIGS. 6 and 7 illustrate an example embodiment of a valve member 90,which may be used in the example venturi valve 10 of FIG. 1. FIG. 6 is aperspective view of the valve member 90, and FIG. 7 is a schematic sideview of the valve member 90. The valve member 90 may include a cone 91and a funnel 92. The cone 91 is positioned upstream of the funnel 92.The cone 91 may be curved and may include a hemispherical, or domeshape, while the funnel 92 may include a frustoconical shape. The cone91 and the funnel 92 may be configured such that when the valve member90 is assembled, a larger end of the funnel 92 may fit within an openend of the cone 91, although this is not explicitly shown.

As shown in FIG. 6, the valve member 90 includes a plurality of distinctflow influencing features 70, which may include a plurality of dimples93. The plurality of dimples 93 may include three rows of concave,hemispherical dimples 93, which may be spaced from one another andstaggered around a reattachment region (shown in FIG. 7) of the valvemember 90. While the valve member 90 is shown as including three rows ofthe plurality of dimples 93, it is contemplated that the valve member 90may include one row of the plurality of dimples 93, two rows of theplurality of dimples 93, four rows of the plurality of dimples 93, orany other suitable number of rows, as desired. In some cases, each rowof the plurality of dimples 93 may include eighty dimples 93. In somecases, each row of the plurality of dimples 93 may include twentydimples, forty dimples, fifty dimples, one hundred dimples, or any othersuitable number of dimples. While the plurality of dimples 93 are shownas having a concave, hemispherical shape, it is contemplated that theplurality of dimples 93 may include a concave conical shape, a concavecube shape, a concave cylindrical shape, a concave rectangular shape, orany other suitable shape. In some cases, the plurality of dimples 93 mayeach include a diameter of 0.25 inches. In some cases, the plurality ofdimples 93 may include a diameter of 0.12 inches, 0.3 inches, 0.5inches, or any other suitable diameter.

As shown in FIG. 7, the valve member 90 may include a central axis 97,which may extend centrally along a length of the valve member 90, amaximum width region 69, which may define the maximum width 94 of thevalve member 90, a reattachment region 95, which may be positioneddownstream of the maximum width region 69, and a separation region 96,which may be positioned downstream of the reattachment region 95. Themaximum width region 69 may be positioned at a point on the cone 91where the cone 91 and the funnel 92 meet, but this is not required. Thecurved, hemispherical shape of the cone 91 may be positioned upstream ofthe maximum width region 69, and thus may be configured to divert airflow towards the maximum width region 69.

In some cases, as shown in FIG. 7, the reattachment region 95 mayinclude the plurality of flow influencing features 70, which may includethe plurality of dimples 93, as discussed with reference to FIG. 6. Thereattachment region 95 may be configured to cause air flowing over themaximum width region 69 to reattach to the valve member 90 in thereattachment region 95. Having the airflow reattach in the reattachmentregion 95 allows the plurality of dimples 93 to influence the reattachedairflow, such as straighten or partially laminarize the reattachedairflow along the reattachment region 95. While not required, the airflow that reattaches to the valve member 90 in the reattachment region95 may be configured to separate from the valve member 90 within aseparation region 96.

FIG. 8 illustrates an example embodiment of a valve member 120, whichmay be used in the example venturi valve 10 of FIG. 1. FIG. 8 is aschematic side view of the valve member 120. The valve member 120 mayinclude a cone 121 and a funnel 122. The cone 121 may be positionedupstream of the funnel 122. The cone 121 may be curved and may include ahemispherical, or dome shape, while the funnel 122 may include afrustoconical shape. The cone 121 and the funnel 122 may be configuredsuch that when the valve member 120 is assembled, a larger end of thefunnel 122 may fit within an open end of the cone 121, although this isnot explicitly shown. As shown in FIG. 8, the valve member 120 mayinclude a central axis 127, which may extend centrally along a length ofthe valve member 120, a maximum width region 119, which may define themaximum width 124 of the valve member 120, a reattachment region 125,which may be positioned downstream of the maximum width region 119, anda separation region 126, which may be positioned downstream of thereattachment region 125. The maximum width region 119 may be positionedat a point on the cone 121 where the cone 121 and the funnel 122 meet,although this is not required. The curved, hemispherical shape of thecone 121 may be positioned upstream of the maximum width region 119, andthus may be configured to divert air flow towards the maximum widthregion 119.

In some cases, as shown in FIG. 8, the cone 121 of the valve member 120may include a higher aspect ratio as compared to other exampleembodiments. Further, the reattachment region 125 may include a contourthat may be one, two, three or more inches in length from the upstreamend 50 of the reattachment region 125 to the downstream end 51 of thereattachment region 125. These lengths are just examples. In the exampleshown, a notch 123 may be formed just downstream of the maximum widthregion 119, between the cone 121 and the upstream end 50 of thereattachment region 125 of the valve member 120. The notch 123, whichmay create a gap where the cone 121 meets the funnel 122. The gap maycreate a low pressure region that draws the airflow down toward thevalve member 120 in the reattachment region 125. The reattachment region125 may then cause air flowing over the maximum width region 119 toreattach to the valve member 120 in the reattachment region 125. The airflow that reattaches to the valve member 120 in the reattachment region125 may be configured to separate from the valve member 120 within theseparation region 126, but this is not required.

FIG. 9 illustrates an example embodiment of a valve member 130, whichmay be used in the example venturi valve 10 of FIG. 1. FIG. 9 is aschematic side view of the valve member 130. The valve member 130 mayinclude a cone 131 and a funnel 132. The cone 131 is positioned upstreamof the funnel 132. The cone 131 may be curved and may include ahemispherical, or dome shape, while the funnel 132 may include afrustoconical shape, but this is not required. The cone 131 and thefunnel 132 may be configured such that when the valve member 130 isassembled, a larger end of the funnel 132 may fit within an open end ofthe cone 131, although this is not explicitly shown. As shown in FIG. 9,the valve member 130 may include a central axis 137, which may extendcentrally along a length of the valve member 130, a maximum width region169, which may define the maximum width 134 of the valve member 130, areattachment region 135, which may be positioned downstream of themaximum width region 169, and a separation region 136, which may bepositioned downstream of the reattachment region 135. The maximum widthregion 169 may be positioned at a point on the cone 131 where the cone131 and the funnel 132 meet, but this is not required. The curved,hemispherical shape of the cone 131 may be positioned upstream of themaximum width region 169, and thus may be configured to divert air flowtowards the maximum width region 169.

In some cases, as shown in FIG. 9, the cone 131 of the valve member 130may include a higher aspect ratio as compared to other exampleembodiments. Further, the reattachment region 135 may include a contourthat may be one, two, three or more inches in length from the upstreamend 50 of the reattachment region 135 to the downstream end 51 of thereattachment region 135. These lengths are just examples. A step 133 maybe formed just downstream of the maximum width region 169, between thecone 131 and the reattachment region 135 of the valve member 130. Insome cases, the step 133 may include a chamfer for a gradual transitionfrom the maximum width region 169 to the reattachment region 135. Thereattachment region 135 may then cause air flowing over the maximumwidth region 169 to reattach to the valve member 130 in the reattachmentregion 135. The airflow that reattaches to the valve member 130 in thereattachment region 135 may be configured to separate from the valvemember 130 within the separation region 136, but this is not required.

FIGS. 10 and 11 illustrate an example embodiment of a valve member 140,which may be used in the example venturi valve 10 of FIG. 1. FIG. 10 isa perspective view of the valve member 140, and FIG. 11 is a schematicside view of the valve member 140. The valve member 140 may include acone 141 and a funnel 142. The cone 141 is positioned upstream of thefunnel 142. The cone 141 may be curved and may include a hemispherical,or dome shape, while the funnel 142 may include a frustoconical shape.The cone 141 and the funnel 142 may be configured such that when thevalve member 140 is assembled, a larger end of the funnel 142 may fitwithin an open end of the cone 141, although this is not explicitlyshown. As shown in FIG. 10, the valve member 140 may include one or moredistinct flow influencing features 70, which may include one or moregrooves 143. The one or more grooves 143 may include a helical groovearound a reattachment region (shown in FIG. 11) of the valve member 140.

As shown in FIG. 11, the valve member 140 may include a central axis147, which may extend centrally along a length of the valve member 140,a maximum width region 179, which may define the maximum width 144 ofthe valve member 140, a reattachment region 145, which may be positioneddownstream of the maximum width region 179, and a separation region 146,which may be positioned downstream of the reattachment region 145. Themaximum width region 179 may be positioned at a point on the cone 141where the cone 141 and the funnel 142 meet, although this is notrequired. The curved, hemispherical shape of the cone 141 may bepositioned upstream of the maximum width region 179, and thus may beconfigured to divert air flow towards the maximum width region 179.

In some cases, as shown in FIG. 11, the reattachment region 145 mayinclude the one or more grooves 143, as discussed with reference to FIG.10. The reattachment region 145 may be configured to cause air flowingover the maximum width region 179 to reattach to the valve member 140 inthe reattachment region 145. In some cases, the airflow that reattachesto the valve member 140 in the reattachment region 145 may be configuredto separate from the valve member 140 within the separation region 146.

FIG. 12 illustrates an example embodiment of a valve member 150, whichmay be used in the example venturi valve 10 of FIG. 1. FIG. 12 is aschematic side view of the valve member 150. The valve member 150 mayinclude a cone 151 and a funnel 152. The cone 151 is positioned upstreamof the funnel 152. The cone 151 may be curved and may include ahemispherical, or dome shape, while the funnel 152 may include afrustoconical shape. The cone 151 and the funnel 152 may be configuredsuch that when the valve member 150 is assembled, a larger end of thefunnel 152 may fit within an open end of the cone 151, although this isnot explicitly shown.

As shown in FIG. 12, the valve member 150 may include a plurality ofdistinct flow influencing features 70, which may include a plurality ofriblets 153. The plurality of riblets 153 may include shallow lineargrooves aligned with the air flow stream, as shown in more detail inCircle A. The plurality of riblets 153 may include a depth of 0.01inches, and may include at least 2,000 riblets 153. In some cases, theplurality of riblets 153 may include more than 2,000 riblets, such as,for example, 5,000, 10,000, or less than 2000, or any suitable number.As shown in FIG. 12, the valve member 150 may include a central axis157, which may extend centrally along a length of the valve member 150,a maximum width region 158, which may define the maximum width 154 ofthe valve member 150, a reattachment region 155, which may be positioneddownstream of the maximum width region 1548 and a separation region 156,which may be positioned downstream of the reattachment region 155. Themaximum width region 158 may be positioned at a point on the cone 151where the cone 151 and the funnel 152 meet, but this is not required.The curved, hemispherical shape of the cone 151 may be positionedupstream of the maximum width region 158, and thus may be configured todivert air flow towards the maximum width region 158.

In some cases, as shown in FIG. 12, the reattachment region 155 mayinclude the plurality of riblets 153. The reattachment region 155 may beconfigured to cause air flowing over the maximum width region 158 toreattach to the valve member 150 in the reattachment region 155. In somecases, the airflow that reattaches to the valve member 150 in thereattachment region 155 may be configured to separate from the valvemember 150 within the separation region 156.

FIG. 13 is a schematic side view of an example venturi valve 500,wherein a valve throat 520 of the venturi valve 500 includes a pluralityflow influencing features 570. The venturi valve 500 may be an exampleof the venturi valve 10, as discussed with reference to FIGS. 1-3, butthis is not required. The venturi valve 500 may include a housing 512having an inner wall 511 that defines the valve throat 520, and a valvemember 540. The valve member 540 may be an example of the valve member40, as discussed with reference to FIGS. 1-3, or may be one of the valvemembers described in FIGS. 4-12. As shown in FIG. 13, the venturi valve500 may include a plurality of distinct flow influencing features 570which may extend inward from the inner wall 511 of the valve housing 512at or adjacent to the valve throat 520. In some cases, the plurality ofdistinct flow influencing features 570 may extend inward from the innerwall 511 of the valve housing 512 upstream and/or downstream of thevalve throat 520. In some cases, the plurality of flow influencingfeatures 570 may extend inward from the inner wall 511 of the valvehousing 512 at or adjacent a broadening section 513 of the valve housing512. The plurality of flow influencing features 570 may be configured toreduce perturbations in an air flow passing along the inner wall 511 ofthe valve housing 512 in a manner similar to that previously discussed.

FIG. 14 is a schematic end view showing the valve throat 520 of theventuri valve 500 of FIG. 13. As can be seen, the valve throat 520 mayinclude the plurality of flow influencing features 570, which mayinclude a plurality of protrusions 563. The plurality of protrusions 563may include a plurality of rectangular tabs that extend inward from theinner wall 511 of the valve housing 512 (as shown in FIG. 13). Theplurality of protrusions 563 may extend out from the inner wall by 3/16inches, however this is merely an example, and the plurality ofprotrusions 563 may extend out any suitable distance. In some examples,the plurality of protrusions 563 may include twenty rectangular tabsdistributed around the valve throat 520. In other examples, as shown inFIG. 14, the plurality of protrusions 563 may include twenty-fourrectangular tabs. In some cases, the plurality of protrusions 563 mayinclude ten rectangular tabs, thirty rectangular tabs, forty rectangulartabs, or any other suitable number of rectangular tabs. While theplurality of protrusions 563 is illustrated as having a rectangularshape, it is contemplated that the plurality of protrusions 563 mayinclude a conical shape, a cube shape, a cylindrical shape, ahemispherical shape, or any other suitable shape.

FIG. 15 is a schematic end view showing the valve throat 520 of theventuri valve 500 of FIG. 13. As can be seen, the valve throat 520 mayinclude the plurality of flow influencing features 570, which mayinclude a plurality of protrusions 573. The plurality of protrusions 573may extend inward from the inner wall 511 of the valve housing 512. Theplurality of protrusions 573 may include two rows of hemisphericalprotrusions 573, which may be spaced from one another and staggered ator adjacent to the valve throat 520 of the valve housing 512. While thevalve throat 520 is shown as including two rows of the plurality ofprotrusions 573, it is contemplated that the valve throat 520 mayinclude one row of the plurality of protrusions 573, three rows of theplurality of protrusions 573, four rows of the plurality of protrusions573, or any other suitable number of rows, as desired. In some cases,each row of the plurality of protrusions 573 may include eightyprotrusions 573. In some cases, each row of the plurality of protrusions573 may include twenty protrusions, forty protrusions, fiftyprotrusions, one hundred protrusions, or any other suitable number ofprotrusions. While the plurality of protrusions 573 are shown as havinga hemispherical shape, it is contemplated that the plurality ofprotrusions 573 may include a conical shape, a cube shape, a cylindricalshape, a rectangular shape, or any other suitable shape.

FIGS. 16 and 17 illustrate an example embodiment of the venturi valve500 including a valve member 580. FIG. 16 is a schematic side view ofthe venturi valve 500, wherein the valve throat 520 of the venturi valve500 includes flow influencing features 570, which may include aplurality of protrusions 584 (shown in FIG. 17), and a valve member 580includes flow influencing features 583. FIG. 17 is an end view showingthe valve throat 520 of the venturi valve 500 of FIG. 16. The flowinfluencing features 583 of the valve member 580 may include a pluralityof protrusions 583. The plurality of protrusions 583 and 584 may includethree rows of hemispherical protrusions 583, 584, which may be spacedfrom one another and staggered around a reattachment region (not shown)of the valve member 580 and/or the valve throat 520. While the valvemember 580 and the valve throat 520 are shown as including three rows ofthe plurality of protrusions 583, 584, it is contemplated that the valvemember 580 and the valve throat 520 may include one row of the pluralityof protrusions 583, 584, two rows of the plurality of protrusions 583,584, four rows of the plurality of protrusions 583, 584, or any othersuitable number of rows, as desired. In some cases, each row of theplurality of protrusions 583, 584, may include eighty protrusions 583,584. In some cases, each row of the plurality of protrusions 583, 584may include twenty protrusions, forty protrusions, fifty protrusions,one hundred protrusions, or any other suitable number of protrusions.While the plurality of protrusions 583, 584 are shown as having ahemispherical shape, it is contemplated that the plurality ofprotrusions 583, 584 may include a conical shape, a cube shape, acylindrical shape, a rectangular shape, or any other suitable shape.

FIGS. 18-27 show graphs illustrating points of audible rattling and norattling at various flow rates and differential pressures of variousventuri valves under test including various valve member disclosedherein. The data was collected by listening for rattle of each testedvalve member at various flow rates and differential pressures. The flowrates are expressed in cubic feet per minute (CFM) and the differentialpressures are expressed in inches of water (WC). The data for eachventuri valve under test was then plotted on its respective graph.

FIG. 18 is a graph 200 illustrating points of audible rattling 204 andno rattling 203 of the valve member 40 as in FIGS. 1-3, where the valvemember 40 does not include a reattachment region and/or flow influencingfeatures and the valve housing does not include flow influencingfeatures. That is, the data shown in FIG. 18 is taken on a prior artventuri valve that does not have any of the benefits disclosed by thepresent disclosure. As shown in graph 200, an audible rattling 204 wasfirst heard around 1200 CFM and 0.6 inch WC, as indicated at point 205.The audible rattling 204 was still heard at a flow rate of around 2100CFM and 0.6 inch WC, as indicated at point 206. As the differentialpressure 202 increased, the audible rattling 204 first occurs at bithigher flow rates 201. For example, when the differential pressure 202was 2.1 inch WC, the audible rattling 204 began to occur at around 1600CFM.

FIG. 19 is a graph 210 illustrating points of audible rattling 214 andno rattling 213 of the valve member 80 of FIGS. 4-5. As shown in FIGS.4-5, the valve member 80 includes a reattachment region 85 and aplurality of flow influencing features 70. The plurality of flowinfluencing features 70 of FIGS. 4-5 include a plurality of protrusions83. In summary, as can be seen in the graph 210, an audible rattling 214was first heard at a flow rate of around 2100 CFM and a differentialpressure of around 0.6 inch WC, as indicated at point 215. As shown, theaudible rattling 214 was still heard at a flow rate of around 2700 CFMand a differential pressure of 0.7 inch WC, as indicated at point 216.When the differential pressure was increased to 2.2 inch WC, there wasno audible rattling 214 over all tested flow rates. As can be seen, thevalve member 80 of FIGS. 4-5 performed significantly better than theprior art venturi valve tested in FIG. 18.

FIG. 20 is a graph 220 illustrating points of audible rattling 224 andno rattling 223 of the valve member 90 of FIGS. 6-7. As shown in FIGS.6-7, the valve member 90 includes a reattachment region 95 and aplurality of flow influencing features 70. The plurality of flowinfluencing features 70 of FIGS. 6-7 include a plurality of dimples 93.In summary, and as can be seen in the graph 220, an audible rattling 224was first heard at a flow rate of around 1650 CFM and a differentialpressure of around 0.6 inch WC, as indicated at point 225. The audiblerattling 224 was still heard at a flow rate of around 2300 CFM and adifferential pressure of 1.0 inch WC, as indicated at point 226. Whenthe differential pressure was increased to 2.1 inch WC, there was noaudible rattling 224 over all tested flow rates. As can be seen, thevalve member 90 of FIGS. 6-7 performed significantly better than theprior art venturi valve tested in FIG. 18.

FIG. 21 is a graph 230 illustrating points of audible rattling 234 andno rattling 233 of the valve member 120 of FIG. 8. As shown in FIG. 8,the valve member 120 includes a reattachment region 125. In summary, ascan be seen in the graph 230, an audible rattling 234 was first heard ata flow rate of around 1600 CFM and a differential pressure of around 0.7inch WC, as indicated at point 235. As shown, the audible rattling 234was still heard at a flow rate of around 1800 CFM and a differentialpressure of 0.6 inch WC, as indicated at point 236. When thedifferential pressure was increased to 2.3 WC, there was no audiblerattling 234 across all tested flow rates. As can be seen, the valvemember 120 of FIG. 8 performed significantly better than the prior artventuri valve tested in FIG. 18.

FIG. 22 is a graph 240 illustrating points of audible rattling 244 andno rattling 243 of the valve member 130 of FIG. 9. As shown in FIG. 9,the valve member 130 includes a reattachment region 135. In summary, ascan be seen in the graph 240, an audible rattling 244 was first heard ata flow rate of around 1300 CFM and a differential pressure of around 0.6inch WC, as indicated at point 245. The audible rattling 244 was stillheard at a flow rate 241 of around 2800 CFM and a differential pressureof 1.1 inch WC, as indicated at point 246. When the differentialpressure was increased to 2.2 inch WC, there was no audible rattling 244across all tested flow rates. As can be seen, the valve member 130 ofFIG. 9 performed significantly better than the prior art venturi valvetested in FIG. 18.

FIG. 23 is a graph 250 illustrating points of audible rattling 254 andno rattling 253 of the valve member 140 of FIGS. 10-11. As shown inFIGS. 10-11, the valve member 140 includes a reattachment region 145 anda plurality of flow influencing features 70. The plurality of flowinfluencing features 70 of FIGS. 10-11 include a groove 143. In summary,as can be seen in the graph 250, an audible rattling 254 was first heardat a flow rate of around 1300 CFM and a differential pressure of around0.5 inch WC, as indicated at point 255. The audible rattling 254 wasstill heard at a flow rate of around 1900 CFM and a differentialpressure of 0.65 inch WC, as indicated at point 256. When thedifferential pressure was increased to 2.2 inch WC, there was no audiblerattling 254 across all tested flow rates. As can be seen, the valvemember 140 of FIGS. 10-11 performed significantly better than the priorart venturi valve tested in FIG. 18.

FIG. 24 is a graph 260 illustrating points of audible rattling 264 andno rattling 263 of the valve member 150 of FIG. 12. As shown in FIG. 12,the valve member 150 includes a reattachment region 155 and a pluralityof flow influencing features 70. The plurality of flow influencingfeatures 70 of FIG. 12 include a plurality of riblets 153. In summary,as can be seen in the graph 260, an audible rattling 264 was first heardat a flow rate of around 1500 CFM and a differential pressure of around0.5 inch WC, as indicated at point 265. The audible rattling 264 wasstill heard at a flow rate of around 2500 CFM and a differentialpressure of 1.0 inch WC, as indicated at point 266. When thedifferential pressure was increased to 2.2 inch WC, there was no audiblerattling 264 across all tested flow rates. As can be seen, the valvemember 150 of FIG. 12 performed significantly better than the prior artventuri valve tested in FIG. 18.

FIG. 25 is a graph 270 illustrating points of audible rattling 274 andno rattling 273 of the valve throat 520 of FIG. 14. As shown in FIG. 14,the valve throat 520 includes the plurality of flow influencing features70. The plurality of flow influencing features 570 of FIG. 14 include aplurality of protrusions 563. In summary, as can be seen in the graph270, an audible rattling 274 was first heard at a flow rate of around2000 CFM and a differential pressure of around 1.0 inch WC, as indicatedat point 275. The audible rattling 274 was still heard at a flow rate ofaround 1900 CFM and a differential pressure of 1.1 inch WC, as indicatedat point 276. When the differential pressure was increased to 2.1 inchWC, there was no audible rattling 274 across all tested flow rates.

FIG. 26 is a graph 280 illustrating points of audible rattling 284 andno rattling 283 of the valve throat 520 of FIG. 15. As shown in FIG. 15,the valve throat 520 includes the plurality of flow influencing features570. The plurality of flow influencing features 570 of FIG. 15 include aplurality of protrusions 573, wherein the plurality of protrusions 573are staggered. In summary, as can be seen in the graph 280, there is noaudible rattling 284 across all tested flow rates, ranging from 100 CFMto 2400 CFM, and all tested differential pressures, ranging from 0.5 WCto 2.3 WC.

FIG. 27 is a graph 290 illustrating points of audible rattling 294 andno rattling 293 of the valve throat 520 and the valve member 580 as inFIGS. 16-17. As shown in FIGS. 16-17, the valve throat 520 includes theplurality of flow influencing features 570, and the valve member 580includes the plurality of protrusions 583. The plurality of flowinfluencing features 570 of FIGS. 16-17 include a plurality ofprotrusions 584. In summary, as can be seen in the graph 290, there isno audible rattling 294 across all tested flow rates, ranging from 100CFM to 2600 CFM, and all tested differential pressures, ranging from 0.5WC to 2.3 WC.

FIG. 28A is a wave graph 300 illustrating a level of sound 301, which ismeasured in decibels (dB), created over time 302, which is measured inseconds (s), for the valve member 40 of FIGS. 1-3, where the valvemember 40 does not include a reattachment region and/or flow influencingfeatures and the valve housing does not include flow influencingfeatures. That is, the data shown in FIG. 28A is taken on a prior artventuri valve that does not have any of the benefits disclosed by thepresent disclosure.

As shown in FIG. 28A, a soundwave 305 hovers around 52 to 56 dB, asindicated at 304. In some cases, an audible rattling occurs, asindicated by a crest 303. The wave graph 300 may include various crests,which indicate audible rattling. As shown in the wave graph 300, audiblerattling occurred at least four times within a five second time 302period. In contrast, as shown in FIG. 28B, which is a wave graph 310illustrating a level of sound 311 created over time 312, by the valvemember 80, as in FIGS. 4-5, the soundwave 315 hovers within a range of55 dB to 59 dB over a five second time 312 period. As shown in FIG. 28B,there is no significant audible rattling produced by the venturi valvewhen the valve member 80 is used.

All numbers are herein assumed to be modified by the term “about”,unless the content clearly dictates otherwise. The recitation ofnumerical ranged by endpoints includes all numbers subsumed within thatrange (e.g., 1 to 5 includes, 1, 1.5, 2, 2.75, 3, 3.8, 4, and 5).

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” include the plural referents unless thecontent clearly dictates otherwise. As used in this specification andthe appended claims, the term “or” is generally employed in its senseincluding “and/or” unless the content clearly dictates otherwise.

It is noted that references in the specification to “an embodiment”,“some embodiments”, “other embodiments”, etc., indicate that theembodiment described may include a particular feature, structure, orcharacteristic, but every embodiment may not necessarily include theparticular feature, structure, or characteristic. Moreover, such phrasesare not necessarily referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with an embodiment, it is contemplated that the feature,structure, or characteristic may be applied to other embodiments whetheror not explicitly described unless clearly stated to the contrary.

Having thus described several illustrative embodiments of the presentdisclosure, those of skill in the art will readily appreciate that yetother embodiments may be made and used within the scope of the claimshereto attached. It will be understood, however, that this disclosureis, in many respects, only illustrative. Changes may be made in details,particularly in matters of shape, size, arrangement of parts, andexclusion and order of steps, without exceeding the scope of thedisclosure. The disclosure's scope is, of course, defined in thelanguage in which the appended claims are expressed.

What is claimed is:
 1. A valve apparatus comprising: a venturi valvehousing that houses a valve member, wherein the valve member is movablein an axial direction of the valve housing, the valve member including:a maximum width region that defines a maximum width of the valve member;a first region downstream of the maximum width region; a second regiondownstream of the first region; wherein the first region tapers radiallyinward, the second region tapers radially inward from the first region,and wherein the first region and the second region do not have the sametaper; and wherein the first region includes a plurality of distinctflow influencing features including a plurality of protrusions.
 2. Thevalve apparatus of claim 1, wherein the valve member has a central axisextending centrally along the length of the valve member, and whereinthe first region has an upstream end and a downstream end with an anglein the range of 5 and 40 degrees between: a first axis extending outfrom the upstream end of the first region and parallel with the centralaxis of the valve member; and a second axis intersecting the first lineat the upstream end of the first region, extending to the downstream endof the first region, and intersecting the central axis of the valvemember.
 3. The valve apparatus of claim 2, wherein the angle is in therange of 25 to 35 degrees.
 4. The valve apparatus of claim 1, furthercomprising an upstream region upstream of the maximum width region,wherein the upstream region has a curved shaped diverting air flowtowards the maximum width region.
 5. The valve apparatus of claim 4,wherein the upstream region is domed shaped.
 6. The valve apparatus ofclaim 1, wherein the first region has a length of at least one inch. 7.The valve apparatus of claim 1, wherein the second region tapersradially inward more than the first region.
 8. A valve apparatuscomprising: a venturi valve housing that houses a valve member, whereinthe valve member is movable in an axial direction of the valve housing,the valve member including: a maximum width region that defines amaximum width of the valve member; a first region downstream of themaximum width region; a second region downstream of the first region;wherein the first region tapers radially inward, the second regiontapers radially inward from the first region, and wherein the firstregion and the second region do not have the same taper; and wherein thefirst region includes a plurality of distinct flow influencing featuresincluding a plurality of dimples.
 9. The valve apparatus of claim 8,wherein the valve member has a central axis extending centrally alongthe length of the valve member, and wherein the first region has anupstream end and a downstream end with an angle in the range of 5 and 40degrees between: a first axis extending out from the upstream end of thefirst region and parallel with the central axis of the valve member; anda second axis intersecting the first line at the upstream end of thefirst region, extending to the downstream end of the first region, andintersecting the central axis of the valve member.
 10. The valveapparatus of claim 9, wherein the angle is in the range of 25 to 35degrees.
 11. The valve apparatus of claim 8, further comprising anupstream region upstream of the maximum width region, wherein theupstream region has a curved shaped diverting air flow towards themaximum width region.
 12. The valve apparatus of claim 11, wherein theupstream region is domed shaped.
 13. The valve apparatus of claim 8,wherein the first region has a length of at least one inch.
 14. Thevalve apparatus of claim 8, wherein the second region tapers radiallyinward more than the first region.
 15. A valve apparatus comprising: aventuri valve housing that houses a valve member, wherein the valvemember is movable in an axial direction of the valve housing, the valvemember including: a maximum width region that defines a maximum width ofthe valve member; a first region downstream of the maximum width region;a second region downstream of the first region; wherein the first regiontapers radially inward, the second region tapers radially inward fromthe first region, and wherein the first region and the second region donot have the same taper; and wherein the first region includes aplurality of distinct flow influencing features including a plurality ofgrooves and/or riblets.
 16. The valve apparatus of claim 15, wherein thevalve member has a central axis extending centrally along the length ofthe valve member, and wherein the first region has an upstream end and adownstream end with an angle in the range of 5 and 40 degrees between: afirst axis extending out from the upstream end of the first region andparallel with the central axis of the valve member; and a second axisintersecting the first line at the upstream end of the first region,extending to the downstream end of the first region, and intersectingthe central axis of the valve member.
 17. The valve apparatus of claim16, wherein the angle is in the range of 25 to 35 degrees.
 18. The valveapparatus of claim 15, wherein the first region has a length of at leastone inch.
 19. The valve apparatus of claim 15, wherein the second regiontapers radially inward more than the first region.
 20. The valveapparatus of claim 15, wherein the plurality of distinct flowinfluencing features include a plurality of parallel grooves, andwherein the plurality of parallel grooves extend lengthwise in adownstream direction.